"I've lived this long to meet you", replied the 85-year-old, wiping away tears as she clasped a photograph of her brother in his youth. They are now 92 and 72 years old, respectively.
"I want to ask them what his dying wish was and what he said about me", Park said in a telephone interview last week.
The reunions are resuming after a three-year hiatus as the North accelerated its pursuit of nuclear weapons and ballistic missiles and relations deteriorated.
For years, Seoul has called for regular meetings between separated families, including the use of video conferences, but the programme often fell victim to fragile ties.
But while Kim and US President Donald Trump held a landmark summit in Singapore in June, Pyongyang has yet to make clear what concessions it is willing to make on its nuclear arsenal, while Washington is looking to maintain sanctions pressure on it.
A hundred people were chosen by each side to attend the reunion.
"It is a shame for both governments that numerous families have passed away without knowing whether their lost relatives were alive", he told presidential secretaries at a meeting.
The family reunion is the result of an agreement their leaders reached in April to address humanitarian issues arising from almost seven decades of division caused by the Korean War.
After 11 hours together over the next three days, the pair will part, nearly certainly never to see each other again, and - unless something changes - they won't even be able to exchange letters.More news: Is Aaron Ramsey really worth £250000 a week?
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More than 130,000 South Koreans have signed up for a reunion since the events began but a lot of them have since died.
For Lee Jong-shik, 81, Monday's reunion was a hard-won second chance to track down his younger brother, Ri Chong Song, after the failure of a 2009 effort when a different individual showed up, to the dismay of the family from the South.
Pak Sam Dong pointed at one of the images, telling his brother: "This is you".
Baik, who will meet his daughter-in-law and granddaughter, said he had packed clothes, underwear, 30 pairs of shoes, toothbrushes and toothpaste as gifts.
Among the relatives was Lee Keum-seom, now a tiny and frail 92, who was to see her son for the first time since she and her infant daughter were separated from him and her husband as they fled.
"It is a shame for both governments in the South and the North that numerous families have passed away without knowing whether or not their lost relatives were alive", he said.
Many participants are elderly, with 35 members of the South Korean group older than 90 and the oldest member at 101 years old.
Several doctors and nurses are travelling with the group to set up an emergency medical centre for the elderly participants.
Numerous family members brought gifts for their North Korean relatives.
"They don't know what their father looks like so I will tell them what he looked like and when he died", Jang said.